1. Field of the Invention
The present invention relates to an aqueous dispersion comprising the reaction product of trimellitic anhydride and a polyol.
2. Background Information
Coatings for automotive applications such as primers and topcoats typically have a number of desirable properties. For example, use of low amounts of organic solvent in a coating composition is often desired for environmental reasons. Additionally, a high solid content coating is also often desired so that resin and pigment can be transferred to a substrate surface as efficiently as possible, resulting in increased application robustness. In addition to the properties listed above, the physical properties of a coating such as adhesion, solvent resistance, and/or appearance should meet automotive industry standards. Attaining all of these characteristics is difficult and often certain properties have to be compromised so that other properties can be upgraded. For example, a compromise between (i) the appearance of a particular coating, and (ii) the coating's chip resistance is often taken into consideration when formulating a coating composition since an increase in a coating's appearance typically leads to a decrease in the coating's chip resistance and vice versa. A coating that minimizes and/or eliminates the inverse relationship between a coating's appearance and chip resistance is therefore desired.